(1). Technical Field
The present invention relates to an image processing system, an image forming apparatus, an image processing method, and a program recording medium for embedding information in an image and detecting the information from a printed document in which the information is embedded.
(2). Related Art
In recent years, a problem of information leaks due to fraudulent reproduction of printed confidential document in association with widespread usage of personal computers, printers, and copying machines. In order to avoid the fraudulent reproduction of the confidential document, a method of embedding and outputting information relating a user who performs a printing operation, date and time information, identification of outputted equipment, and so on (hereinafter referred to as tracking information) in the confidential document at the time of printing, and reading the printed original document with a scanner or the like to estimate a source of information leaks by analyzing the user, the client PC, the printer, the date and time, and so on embedded in the read image is well known.
The method of preventing information leaks as described above requires a capability of credible reading of the tracking information embedded in the document. In addition, it is required to be capable of reading the tracking information not only from the original document in which the tracking information is embedded when they are printed out, but also from copy of the original document reproduced by the copying machine.